A review is presented dealing with the use of carbon paste as an electrode maaterial for electrochemical sensors (311 references). It covers mainly publications which appeared during the period 1990–1993; numerous applications demonstrate the widespread applicability of carbon paste in the field of electrochemical analysis, such as voltammetry, amperometry, and potentiometry, but also as an electrode for electrochemical detectors in flow systems.

Sensors based on carbon paste in electrochemical analysis: A review with particular emphasis on the period 1990–1993

Copper (Cu) is a heavy metal which in recent studies has been attributed an increasing role in metabolic processes of plant cells. It is an indispensable component of oxidative enzymes or of particular structural components of cells. At elevated concentrations, Cu can act strongly on chromatin, the photosynthetic apparatus, growth, and senescence processes. The mechanisms of the metal toxicity depending largely on the growth stage of treated plants are presented in this review.

Effect of copper on cellular processes in higher plants

Kinetics and Mechanisms of Formation and Reactivity of Non-heme Iron Oxygen Intermediates

Indolizidine and quinolizidine alkaloids

The electron self-exchange rate constants of blue copper model complexes, [(-)-sparteine-N,N'](maleonitriledithiolato-S,S')copper ([Cu(SP)(mmt)])(0/)(-), bis(2,9-dimethy-1,10-phenanthroline)copper ([Cu(dmp)(2)](2+/+)), and bis(1,10-phenanthroline)copper ([Cu(phen)(2)](2+/+)) have been determined from the rate constants of electron transfer from a homologous series of ferrocene derivatives to the copper(II) complexes in light of the Marcus theory of electron transfer. The resulting electron self-exchange rate constant increases in the order: [Cu(phen)(2)](2+/+) < [Cu(SP)(mmt)](0/)(-) < [Cu(dmp)(2)](2+/+), in agreement with the order of the smaller structural change between the copper(II) and copper(I) complexes due to the distorted tetragonal geometry. The dye-sensitized solar cells (DSSC) were constructed using the copper complexes as redox couples to compare the photoelectrochemical responses with those using the conventional I(3)(-)/I(-) couple. The light energy conversion efficiency (eta) values under illumination of simulated solar light irradiation (100 mW/cm(2)) of DSSCs using [Cu(phen)(2)](2+/+), [Cu(dmp)(2)](2+/+), and [Cu(SP)(mmt)](0/)(-) were recorded as 0.1%, 1.4%, and 1.3%, respectively. The maximum eta value (2.2%) was obtained for a DSSC using the [Cu(dmp)(2)](2+/+) redox couple under the light irradiation of 20 mW/cm(2) intensity, where a higher open-circuit voltage of the cell was attained as compared to that of the conventional I(3)(-)/I(-) couple.

Blue Copper Model Complexes with Distorted Tetragonal Geometry Acting as Effective Electron-Transfer Mediators in Dye-Sensitized Solar Cells

Stereoelectronic properties of metalloenzymes—III: A soluble tetrahedral coordination complex of copper(II)—dichloro(sparteine)copper(II)

A new class of mimic model compounds for the type 1 copper site has been prepared by introducing the maleotritile-dithiolate, C4N2S22-, into the copper(II) sparteine moiety. The copper atom in the ...

A Mimic Molecule of Blue Copper Protein Active Site [(−)-Sparteine-N,N‘](maleonitriledithiolato- S,S‘)copper(II)

Relationships among structure and spectroscopic properties in tetrahedrally distorted copper(II) (−)-sparteine dichloride

Complexes with sulfur and selenium donors. XI. Metal 2-amino-1-cyclopentene-1-dithiocarboxylates

A neutral complex of Cu(II) with the chiral bidentate nitrogen-chelating alkaloid (−)-sparteine, with nitrate groups occupying the remaining coordination sites, has been prepared and characterized. Solution conductivity measurements indicate that both nitrate groups are coordinated to copper to give a neutral molecule. Optical and electron-spin-resonance spectra in toluene/CHCl3, did not show a clear picture of the coordination geometry. A frozen-glass ESR spectrum showed the same evidence for mixed species, with the predominant species characterized by a very low A11 value of 118 G. Crystals 1 and 2 of Cu(C15H26N2)(NO3)2 were grown by two methods: 1 at 25°C from saturated acetonitrile, and 2 at 5°C from ethanol/dichloromethane under CCl4 vapor. Their structures were determined by X-ray crystallography. Crystals 1 were monoclinic, space group P21, with a = 7.851(6), b = 14.408(10), c = 16.079(10) A, β = 97.93(6)°, V = 1801(2) A and Z = 4. Crystals 2 were orthorhombic, space group P212121, with a ...

Sung-Nak Choi

Papers

Stereoelectronic properties of metalloenzymes—III: A soluble tetrahedral coordination complex of copper(II)—dichloro(sparteine)copper(II)

A Mimic Molecule of Blue Copper Protein Active Site [(−)-Sparteine-N,N‘](maleonitriledithiolato- S,S‘)copper(II)

Relationships among structure and spectroscopic properties in tetrahedrally distorted copper(II) (−)-sparteine dichloride

Complexes with sulfur and selenium donors. XI. Metal 2-amino-1-cyclopentene-1-dithiocarboxylates

Molecules of copper(II) l-sparteine dinitrate are mixed four- and five-coordinate in one crystalline phase and only four-coordinate in another.